Safety device for vertically movable doors



June 15, 1965 M. B. ZOLL ETAL SAFETY DEVICE FOR VERTICALLY MOVABLE DOORS 2 Sheets-Sheet 2 Filed Dec.

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INVENTORS MAURICE B." zou. ERVIN R. STALLINGS BY y WM ATTORNEY" United States Patent ice 3,188,698 SAFETY DEVICE FOR VERTICALLY MOVABLE DOORS Maurice ,B. Zoll, Lynnwoorl, Lynnhaven, and Ervin R. Stallings, South Fairview, Va., assignors to. The 3.. G. Wilson Corporation, Norfolk, Va., a corporation of Delaware Filed Dec. 1, 1960, Ser. No. 72,967 8 Claims. (Cl. -9-19) This invention relates to improvements in safety devices or catches to check the downward movement of vertically movable doors, in case of breakage of suspending cables or other accident which would otherwise allow the doors to fall.

An object of our invention is to provide a safety device for a vertically sliding door to prevent the latter from falling, with possible injury to personnel, if the counterbalancing mechanism thereof fails.

Another object of our invention is to provide a device of the character described-which is not dependent on slots in a door guide, to receive teeth of a door-checking device, or a projection on a roller or catch-carrying member.

'A further object of our invention is to provide a safety device of the character described in which the doorcar'rying cable is connected to the door-checking-pawl carrying shaft, as through a crank or arm thereon, rather than directly to the door itself or a member rigidly secured thereto. A still further object of our invention is to provide, in an arrangement as above described, a support for a free end portion of the shaft lever or crankpin thereof, while said pin serves to support the door.

An additional object of our invention is to provide an improved construction for the lever or crank on the shaft of the device, whereby broaching is avoided by the substitution of a construction employing molten metal or solder, thereby facilitating and cheapening the manufacture of the device.

Another object of our invention is to provide, as the checking means for the door, a pawl shaped with respect to the guide channel and provided with a plurality of teeth disposed in a plane so that, after engagement of the first teeth, additional teeth are brought into play as the guide channel is indented and expanded by the pawl, as determined by the weight and velocity of the door at the time of the checking action.

A further object of our invention is to provide a safety catch in the form of a pawl, with teeth disposed along a straight line, so formed as to size and shape that, when the catch is released to effect a checking of the door, a desired wedging action between the pawl and channel of a guide rail occurs to stop descent of the door, with the I employment of only a needed number of teeth which successively engage.

These and other objects and advantages will become apparent from the following detailed description when taken with the accompanying drawings. It will be understood that the drawings are for purposes of illustra- FIG. 2 is a fragmentary horizontal sectional view onv the line IIII of FIG. 1, in the direction of the arrows. FIG. 3 is a fragmentary side elevational view of the structure illustrated in FIG. 1.

gl gfiglgt Patented June 15, 1965 FIG. 4 is an elevational view of the lever or crank assembly of our device with associated hub and pin, illustrating the novel construction thereof.

FIG. 5 is an end elevational view of the structure illustrated in FIG. 4.

FIG. 6 is a perspective view of the parts forming the hub of the crank assembly, illustrated in FIGS. 4 and 5, prior to insertion of the inner non-circular portion into the hollow cylindrical, portion thereof.

FIG. 7 is a side elevational view of the. pin or shaft which carries the. crank assembly of FIGS. 4 and 5, as well as the spring, roller, and pawl of FIGS. 1, 2 and 3.

Referring to the drawings in detail, there is illustrated an embodiment of our invention designed to be used in connection with a vertically sliding door 11 of known construction. The door may be rigid. or formed of a plurality of horizontally hinged or otherwise articulated sections. It is desirably provided at vertically spaced intervals with rollers 12 ,(only one of which is shown) along both of its vertical edges, received in verticallyextending guide rails 13 (only one of which is illustrated) each having achannel 14.

Each guide rail 13 may have a vertically extending web 15 secured to the wall or casing 16 of the building with which the door is used, along a side of the door opening, as by a mounting bracket 17. A horizontally extending shaft (not shown) may be mounted above. the door opening and provided with a pulley (not shown) for taking up or letting out a supporting cable 18. As an illustra tion of such a shaft and pulley for a supporting cable, see the Moler Patent NO.-2,651,817, dated September 15, 1953.

The shaft may be power operated or, as illustrated in said patent, may have a helical spring wound therearound to counterbalance the weight of the door. Although only one supporting cable 18 is illustrated, it will be understood that we may have such a cable adjacent each vertical edge of the door and similar safety apparatus associated therewith. The counterbalancing construction is well known and so is not described in greater detail.

At least one lower corner portion of thedoor 11 carries a mounting plate 19. This plate serves to rotatably support a shaft or pin 21, as by being provided with outstanding bearing brackets 22 and 23. These brackets may be formed separately of the plate 19 and welded or otherwise secured thereto, or they may be slit therefrom and bent out, if so desired. They are desirably braced by receiving and having connected thereto a hollow cylin-.

drical member or tube 24, which forms an elongated bearing for the shaft 21. The shaft'21 carries a release lever or crank assembly 25 which is non-rotatably mounted thereon as by having a hub 26 provided with a non-circular, desirablysquare, aperture 27, to snugly receive the corresponding non-circular or square. end portion 28 of the shaft-21.

The lever assembly 25 is for economy desirably formed as illustrated in detail in FIGS.-4, 5, and 6. That is, the

illustrated in FIG. 5, thereby providing a desired increased clearancewith respect to the plane of the door .11. The

hub 26 of said assembly is formed as a hollow cylindrical metal portion or bushing 29 snugly-fitted in a corresponding aperture laterally offset from said axis in the'lever portion 20 and, in turn,-snugly receiving a non-circular tubular metal member or bushing31, desirably square in section. This member 31 maybe formed peripherally continuous, as by pressing to shape a member of initially hollow cylindrical form. As an alternative, however, the

' flange 39 as the means,.desirably silver solder or other metal 31} which is melted and run into the spaces between the exterior of the part 31 and the interior of the part 29, clo'sing the peripheralbreak, if present, in the member 31, aswell as similarly securing the parts and 29; Thelever or crank assembly is then completed, as by inserting a'pin 32 in a corresponding aperture 33 in the lever portion 24) remote from the hub 26 and welding or otherwise suitably connecting it to said lever portion.

After applying the hub 26 over the non-circular portion 28 of the shaft 21, the roller 12 is applied thereover, followed by the application of the safety catch 'or'locking wedge or pawl 34." This. means that the roller is freely rotatable on the cylindricalremnants 4t on-the non-circular portion 28 of the shaft 21 between the crank assembly25 and the pawl34. I This pawl has a corresponding non-circular or square aperture 35, snuglyreceiving portion of said shaft and encircled by anend portion of the spring 41, and the other end of the spring is locked to the bearing bracket 22, as by passing through an aperture 43 therein and bent over therebeyond as at 4-4. After the connection of the spring 41 to the pin 42 and the bracket'22 is effected, the spring is tensed, as by turning the pawl '34 clockwise, as viewed. in FIG. 3, until the desired amountof torsional tension is imparted thereto.

This spring tension is maintained by connecting the cable l to the pin'32, 'as by providing a grommetdS around which the lower end portion of the cable 18 is wrapped and secured, and through which grommet said pin passes, as viewed most clearlyin FIGS. 1, 2 and 3.

.In order torelieve the pin 32 of stress and prevent posi of an angularbracket.

sible bending thereof, as well as of the lever member 23, we provide acable pin support 46, desirably in the form The base flanged-9 of said bracket is secured to the door fixture 19in any desired manner,

and; the outstandingflange'48 overlies the free end position of the pin 32 and provides an abutment therefor when said pin 32 is in uppermost position as viewed in FIGS.

1, 2 and 3: p

V In normal operation, the door 11 is raised or lowered by operation of the cable 18. Said cable transmits'force tothe door,.not only through the bracket 46, but also through the crank assembly25, shaft 21,.tube 24 and brackets 22 and 23, while the lever 20 extends straight up the correspondingly-formedor squared portion 28 of the shaft 21. The pawl 34 maybe of steel, case-hardened or otherwise provided with a hardened surface. It may be secured to the squared portion in any desired manner, as by a drive fit or by means of a set screw, not'shown... If desired, the non-circular hole 35 may be provided by the use of a bushing non-circular in section (like the bushing 31, for example) and secured in place by molten metal as previously disclosed for the assembly 25, except that the use of a cylindrical bushing thereabout may be omitted. It is desirably shaped as illustrated in the drawings, which are to scale.

of said hole 35 are desirably generally parallel to the plane of the surfacecarryingthe teeth or end portion 36.

'to the axis of the pawl 34 is as illustrated, when used with a guide 13 having achannel of the width illustrated.

By so constructing the pawl, upon release the same will Thus, an opposed pair of the'straight sides from'its shaft 21'. Upon failure of the cable 18, or of the associatedcounter-balancing mechanism, allowing said cable to become slack, the shaft 21, crank assembly 25, and pawl 34 are allowed to quickly turn counter-clockwise, as viewed in FIG. 3, upon the descent of the door 11 under the action ofthe pre-stressed spring 41. This the guide rail 13, and starting to .flange 39, depending on the velocity of descent at the time turn counter-clockwise, from its full line position through ian angle designated 37, to'its position illustrated indotted lines in FIG. 3, whereupon thefirst teeth '38 will bitingly engage the flange 39 of the guide. If the door 11 is at that time dropping at a slow rate of speed, these teeth.

39 m'ay be all that are needed to stop it. However, if

more are needed, they successively come into play as the door descends and the other teeth are drawn toward the in FIG. 3. I

This biting'action occurs, pawl along the flange 39, tween the pawl 34 fact that the pawl by virtue of the relationshinbecarries two parallel rows of desirably mid with a sharp posed at an angle of desirably of said pawl.

gagement there is only a small angle between the toothed portion 36 and the flange 39, so that a strong wedging action occurs, tending to force an increasing number of teeth into locking engagementwith the flange 39 as the biting or indenting is panded.

The means for biasing the pawlj34'into locking engagement with the guide rail 13, in the present embodiefliected'and the guide rail 13 expawl turns counter-clockwise as viewed turning carries the pawl'34 from its normal full-line position to 'that'indicated in dotted lines in FIG.- 3, forcibly jamming the first teeth -38'thereof into the flange 39 of check the downward movement of the door.

This downward movement of the door will be entirely checked upon engagement of: two ormore teeth with the the pin is released, as well as on the tension initially applied to the spring 41, its strength, the weightof the door, the clearance provided between'the roller 12 and theguide rail 1.3, and the resiliency of the flanges of said-rail.

After the door 11' has been stopped, it'may thereafter be raised by hand and connected to a new cable, or to the old one if unbroken up'on' repair of the counterbalancing mechanism, whereupon the cable will again draw the pawl 34 away from'engagement with the flange 33 of the guide rail 13 andallow the door to be moved up or down in a normal manner, guided bytheroller 12 and other rollersconventionally used but not here illustrated. 'Although the safety mechanism at only one rather thania sliding of the a r and the guide rail13, as well as the a side of the door is illustrated,'it will be. understood-that it may be duplicated at the other vertical edge of the door and as'sociated with another operating cable.

- .From the the foregoing disclosure it will be seen that we have provided an improved safety mechanism for vertically sliding doors where an operating cable (or cables) I normally supports '(or support) the door'through the safety mechanism itself,*as'wel1 as through a door bracket cooperating with a part of said mechanism. The pawl 34 which stops the descent of the door, upon failure of the operating or counter-balancing mechanism is specially designed and shaped so as .to gradually bring in the number of teeth necessary to effect complete stoppage of the, door, without the necessity of having slots inthe. guide rail (or rails) to catch said teeth, and without the necessity of piercing said guide rail (or rails) or ment takes the form ofv a helical spring-41.' One end portion of said spring 41 is securedto. the shaft '21, asby means of a pin 42 passing into anaperture 47 in an end otherwise multilating the mechanism, thereby obviating its reuse until repaired. Wedging action is obtained by forming the pawl wedge-shaped, thereby avoiding the necessity'of having a wedging projection on the carrying roller opposite the point of engagement of the pawl with the guide rail.

Having now described our invention in detail in accordance with the patent statutes, those skilled in this art will have no difiiculty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.

We claim:

1. A lever and hub assembly comprising a fiat sheet of metal elongated in shape and with one end portion having an aperture on its longitudinal axis, the other end portion being wider than said axis-apertured end portion, an aperture laterally offset from said axis and formed in said wider end portion, a hollow cylindrical hub fitting the laterally offset aperture, a non-circular bushing fitted into the hollow of said hub and with corners engaging the inner surface thereof, and metal integrating the parts by solidification from the molten state while disposed between said bushing, hollow cylindrical hub and flat sheet.

2. A safety device for a vertically movable door, associated with a vertically extending guide rail having a channel and disposed along a vertical edge of the door, said device comprising a shaft, said shaft having one end portion non-circular in section, means on said door for rotatably supporting said shaft so that it projects laterally into the channel of said guide rail, a pawl movable between door releasing and door checking positions in said channel and operably secured to said shaft, spring means biasing said shaft rotatably so as to tendto move said pawl into door-checking position in said channel, a lever having a hub with an aperture formed to correspond with the non-circular portion of said shaft, in which is non-rotatably fitted said non-circular shaft portion, said lever and hub assembly comprising a flat sheet of metal elongated in shape and with one end portion having an aperture on its longitudinal axis, the other end portion being wider than said axis-apertured end portion, an aperture laterally offset from said axis and formed in said wider end portion, a hollow cylindrical hub fitting the laterally offset aperture, a non-circular bushing fitted into the hollow of said hub and with corners engaging the inner surface thereof, metal integrating the parts by solidification from the molten state while disposed between said bushing, hollow cylindrical hub and flat sheet, and a cable secured to said lever to, as long as it is taut, lift and sustain said door, resist the doorchecking action of said spring means, and thereby prevent the pawl from being moved by said spring means to doorchecking position.

3. A safety device for a vertically movable door associated with a vertically extending guide rail having a channel and disposed along a vertical edge of the door, said device comprising a shaft, means on said door for rotatably supporting said shaft so that it projects laterally into the channel of said guide rail, a pawl movable between door-releasing and door-checking positions in said channel and operably secured to said shaft, spring means biasing said shaft rotatably so as to tend to move said pawl to door-checking position in said channel, a lever secured to said shaft, a pin projecting laterally from said lever, a cable secured to said pin, and a support projecting from said door and overlying a free end portion of said pin, to form a pin abutment for relieving said pin of strain and transmitting force between said cable and said door to, as long as said cable is taut, vertically lift and sustain said door through said lever and shaft while said lever extends straight up therefrom, resist the door-checking action of said spring means, and thereby prevent the pawl from being moved by said spring means to door-checking position.

4. A safety device for a vertically movable door, associated with a vertically extending guide rail having a channel and disposed along a vertical edge of the door, said device comprising a shaft with one end portion noncircular in section, means on said door for rotatably supporting said shaft so that it projects laterally into the channel of said guide rail, a pawl movable between doorreleasing and door-checking positions in said channel and operably secured to said shaft, spring means biasing said shaft rotatably so as to tend to move said pawl to doorchecking position in said channel, a lever as a flat sheet secured to said shaft, the non-circular end portion of said shaft fitted in a correspondingly-formed aperture in said lever, the non-circular portion of said lever being formed by fitting a hollow non-circular bushing within a hollow cylindrical hub portion and securing the three parts together by the use of metal solidified from the molten state while disposed between said flat sheet, hub portion and bushing, and a cable secured to said lever to, as long as it is taut, vertically lift and sustain said door through said lever and shaft while said lever extends straight up therefrom, resist the door-checking action of said spring means, and thereby prevent the pawl from being moved by said spring means to door-checking position.

5. A machine element comprising a lever with a circular hub aperture, a hollow cylindrical hub fitted in said aperture a non-circular tube fitted within said hollow cylindrical hub, and metal consolidating the lever, hub and tube, solidified from the molten state between said consolidated parts.

6. A machine element as recited in claim 5, wherein the non-circular tube is square in section.

7. A machine element as recited in claim 5, wherein the non-circular tube comprises a flat sheet of metal bent to that form.

8. The method of forming a machine element with a non-circular aperture in its hub comprising fitting a hollow cylindrical part in a corresponding aperture in the element to form an apertured hub for said element, fitting a corresponding non-circular tube within said hollow cylindrical part, and filling the spaces between the hollow cylindrical part, the tube and the element, with molten metal.

References Cited by the Examiner UNITED STATES PATENTS 944,534 12/09 Beaman 74-545 1,787,580 1/31 Jasper 287- 2,006,228 6/35 Collins -191 X 2,068,543 1/ 37 Greegor 160-206 X 2,095,695 10/ 37 Greegor 20-19 2,126,519 8/38 Vogel 29-482 2,185,828 1/40 Blodgett 20-19 2,313,312 3/43 Bakewell 287-119 2,691,214 10/54 Schnell et al 29-482 2,948,558 8/60 Schultz 28753 FOREIGN PATENTS 733,460 7/32 France.

CHARLES E. OCONNELL, Primary Examiner.

GEORGE A. NINAS, 1a., JEROME SCHNALL, NOR- TON ANSHER, HARRISON R. MOSELEY,

Examiners. 

1. A LEVER AND HUB ASSEMBLY COMPRISING A FLAT SHEET OF METAL ELONGATE IN SHAPE AND WITH ONE END PORTION HAVING AN APERTURE ON ITS LONGITUDINAL AXIS, THE OTHER END PORTION BEING WIDER THAN SAID AXIS-APERTURED END PORTION, AN APERTURE LATERALLY OFFSET FROM SAID AXIS AND FORMED IN SAID WIDER END PORTION, A HOLLOW CYLINDRICAL HUB FITTING 